finding coordinate of sketch image (eg. scanned as photo format) in r or other software

Question

I want to redraw any sketch within R with polygon. But I need a painstaking work to find coordinates (X or Y values for each points).

enter image description here

Is there any R package or other software that can find coordinates from an image ? Thus output will be data with considerably high number of points (x,y) so that the figure can be recreated.

Edits: ........

Here are examples:

(1) Map outline for example:

enter image description here

Second example:

(2) Object shape example:

enter image description here

jon · Accepted Answer

You can use WebplotDigitizer app, you can use online. Here is snapshot of your example:

enter image description here

Here is output cordinates:

For the second figure cordinates are:

Plot in R:

candlefig <- read.csv(file.choose(), sep = ",", head = TRUE)
plot(rev(candlefig$x), rev(candlefig$y), type = "p", pch = 19, col = "red")

You can increase number of points in the software. However connecting lines in order may be bit problem in complex figure like this.

enter image description here

Online youtube tutorial video is here: For creating map tutorial. ternary diagram polar plot

Helplink:

Greg Snow · Answer

In R you may want to look at the digitize package, it has tools for reading a jpeg image and clicking on the image to get the points for the polygon(s). I belive that some of the spatial packages have some similar functionality for maps, but don't remember which packages).

You can do something similar by plotting your image using the image or rasterImage function (see the EBImage or other packages for reading in the jpeg), then using the locator function (see the type argument) to click on the plot and get the coordinates. If you want to specify a different coordinate system then look at the updateusr function in the TeachingDemos package.

For a more automated approach you can look at the potrace program. Inkscape has a builtin call to potrace with a little nicer interface and more options for preprocessing and postproccessing the image.

finding coordinate of sketch image (eg. scanned as photo format) in r or other software

Tags:

java

r

image-processing

map

matlab

SHRram

2 Answers

jon

Greg Snow

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finding coordinate of sketch image (eg. scanned as photo format) in r or other software

Tags:

java

r

image-processing

map

matlab

SHRram

2 Answers

jon

Greg Snow

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Recent Activity

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